Yes absolutely! Once you've created your account, if you decide that you would like change your email service, just follow these simple steps below:
Click on the service you wish to switch to. In this example we will be switching from Google Apps to Simple Mail
Confirm that you wish to proceed. Keep in mind that your previous account will be deactivated
Enter in the desired name for your new email address and password, then click 'Continue'
You've successfully added the new service, you're almost done!
To finalize the switch, click 'Manage' on the original service. In this example our original service was Google Apps
Click Cancel Service to remove the service from your account
Caution: This step cannot be undone! Click the 'Cancel' button to complete the cancellation
Ta-da! You've successfully switched services.